What does this Pull Request do?

Moves the custom Twig filter TwigTruncate code to a utility class so it can be shared across metadatamanipulators and metadataparsers that use Twig templates.

What's new?

Adds a new MIK utility class, src/utilities/MikTwigExtension.php, that is used within metadatamanipulators and metadataparsers like this:

$truncate_filter = new \Twig_SimpleFilter('TwigTruncate', 'mik\utilities\MikTwigExtension::TwigTruncate');
$twig->addFilter($truncate_filter);

The custom TwigTruncate filter is then available in metadatamanipulators and metadataparsers using logic like this:

{% if Title|length < 30 %}
  <titleInfo>
     <title>{{ Title }}</title>
  </titleInfo>
{% else %}
  <titleInfo>
     <title>{{ Title|TwigTruncate(30) }}</title>
  </titleInfo>
{% endif %}

How should this be tested?

Since this branch makes it possible to share code between a metadata parser and a metadata manipulator, we should test both.

Unzip the attached configuration and data files.
Check out the issue-379 branch and run composer dump-autoload or equivalent.
Test the Templated metadata parser first by running ./mik -c issue_379_parser.ini. Output files will be in /tmp/issue_379_output.
image01.xml, image05.xml, and image05.xml will have titles that have been truncated at the word boundary closest to 30 characters (refer to the input file issue_379_metadata.csv to confirm this is the case).
Delete the /tmp/issue_379_output and /tmp/issue_379_temp directories.
Test the InsertXmlFromTemplate metadata manipulator first by running ./mik -c issue_379_manipulator.ini. Output files will be in /tmp/issue_379_output.
image01.xml, image05.xml, and image05.xml will have titles that have been truncated at the word boundary closest to 30 characters (refer to the input file issue_379_metadata.csv to confirm this is the case).

issue_379.zip